From 1a5cea9ebe9ce06cd601a4be11b80b16104c3311 Mon Sep 17 00:00:00 2001 From: dc Date: Wed, 23 Sep 2026 15:38:37 +0000 Subject: [PATCH] docs(validations): a date formatted column takes no special missing --- docs/dcc-validations.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/docs/dcc-validations.md b/docs/dcc-validations.md index 5921a01..7408514 100644 --- a/docs/dcc-validations.md +++ b/docs/dcc-validations.md @@ -49,6 +49,8 @@ Check back frequently as we keep growing this list of checks. For how each rule A SAS numeric variable has 28 missing values: the regular `.` and 27 special ones (`.A`-`.Z` and `._`). Data Controller accepts them in a numeric cell as a bare letter - `a` to `z`, or `_`, with no period - and stores the matching special missing in SAS. +A numeric column that carries a date, datetime or time format is the exception. Those cells are edited through a date picker rather than the numeric editor, and the picker accepts only a date - so a special missing cannot be typed into one of them. + The rules treat a special missing as a value for some checks and as a missing value for others: |Rule|What happens to a special missing|